To contribute to hemodynamics of pulsatile flow by continued study of wall-shear stress and velocity profiles at bifurcations and other non-uniformities in the aortas. Methods of study are (a) experimental measurements, for velocity, wall-shear stress and distensibility of excised segments of steer aortas in vitro, using a new shear stress gage, a hot film probe and a clip-gage, especially developed for this purpose; (b) computer simulation by finite-element methods.